Cardiac Arrest Due to Pacing Failure From Pilsicainide Poisoning

We experienced a case of accidental pilsicainide poisoning suspected as the cause of pacing failure leading to cardiac arrest. The patient was a 36-year-old woman with a history of refractory multifocal supraventricular tachycardia who had previously undergone multiple cardiac ablations requiring placement of a pacemaker. Upon her arrival on the day of dental treatment, the patient's condition deteriorated rapidly, with a heart rate of approximately 30 beats/min, pacing failure, and an idioventricular rhythm upon electrocardiographic examination. During transportation for emergency medical care, the patient experienced clonic convulsions, and ventricular tachycardia was observed. Cardiopulmonary resuscitation, large-volume infusion, and percutaneous cardiopulmonary support were rapidly performed after arrival at a nearby medical hospital. This elicited a pacing response and successful resuscitation of the patient. No abnormalities were found during pacemaker interrogation; however, the patient's serum pilsicainide concentration was 1.46 μg/mL. Accidental ingestion of pilsicainide likely led to an increase in pacing threshold and...